In many individuals, disease and/or injury may result in the loss of one or more natural teeth. As a result, various techniques have been developed to replace such lost natural teeth with prosthetic appliances.
For example, where sufficient natural teeth remain adjacent to the location where a prosthetic tooth is to be positioned, a bridge may be fabricated.
Alternatively, if insufficient natural teeth remain to support and stabilize a bridge, a denture may be fabricated, with the denture seating against the patient's gingiva.
In still other situations, a dental implant may be used. With such a dental implant, a hole is generally first made in the upper or lower jaw bone, as appropriate, and then the distal end of the implant is fixed in the recipient bone, e.g., by screwing the implant into the bone. The dental implant is generally sized and positioned so that the proximal end of the implant protrudes at least partially into the space where the prosthetic tooth is to be positioned. Then the prosthetic tooth is fixed to the proximal end of the implant, such that the prosthetic tooth generally occupies the space of the lost tooth.
While such dental implants can be effective, they also tend to suffer from a number of problems. Among other things, with current dental implants, the longitudinal axis of the prosthetic tooth must generally follow the longitudinal axis of the implant which is seated in the bone. Unfortunately, the optimal axial alignment for the implant seated in the bone may not necessarily be the same as the optimal axial alignment for the prosthetic tooth extending into the mouth. In particular, it has been found that the optimal axial alignment for the implant tends to be dictated by the specific anatomy of the patient's recipient jaw bone, while the optimal axial alignment of the prosthetic tooth tends to be dictated by the geometry of the patient's bite, lip support, phonetics and aesthetics. Thus, with current dental implants, the dental practitioner typically faces a choice of optimizing the orientation of the restoration for either (1) the implant seated in the bone, or (2) the prosthetic tooth extending into the mouth, or (3) some compromise in between. In any case, the result is generally a compromise of some sort.